The Clinical Core will be responsible for the recruitment, medical assessment, and medical management of study patients. The Department of Physical Medicine and Rehabilitation at the University of Michigan Medical Center has well established treatment programs for, and ready access to, patients with spinal cord injury and brachial plexus injury. The Clinical Core will also administer and monitor the response of patients with chronic pain to antidepressant and anticonvulsant medication used to treat their chronic neuropathic pain. The Clinical Core will provide information regarding the clinical status of patients to the subproject directors, and will also coordinate the timing of data collection for the various subprojects. Finally, the Clinical Core will conduct an investigation to examine the impact of the development of chronic neuropathic pain on thermal and vibratory sensation in dermatomes adjacent to the injured region. This study will also examine the relationship between depression, somatic focus, cognitive distortions, and perceived intensity and unpleasantness of thermal stimulation.